Eighteen people suffered serious injuries, according to the local government website.

Twelve bodies have been identified. They include two local residents and at least six tourists, who were visiting Jiuzhaigou national park, the epicentre of the quake some 285 kilometres north of Chengdu.

The 720-square-kilometre mountainous park, a UNESCO world heritage site known for its karst scenery and waterfalls, was closed when the quake struck at 9:19 pm on Tuesday (1319 GMT), it said.

Tremors from the earthquake were felt in Beijing, more than 1,200 kilometres away.

The U.S. Geological Survey reported a magnitude-6.5 quake, while state media cited a magnitude-7.0 quake.

Chinese monitors have detected multiple landslides but no major building collapses, it said.

The top-level national emergency response continued amid ongoing aftershocks on Thursday, involving at least four helicopters, 90 vehicles, hundreds of soldiers, medical personnel and more than 1,200 rescuers, state television China Central Television (CCTV) reported.

More than 60,000 people, mostly tourists, had been evacuated with help from tourist buses and private vehicles,by 4:30 p.m. on Wednesday, it said.

Some 10,500 people have been moved from damaged buildings to emergency shelters, CCTV said.